1. Field of the Invention
The present invention relates to a blasting device, and particularly relates to a blasting device which is for carrying out a blasting operation and easy to carry.
2. Description of the Related Art
On the occasion of recoating a coated wall surface, a blasting operation of preparing the surface by grinding the coating film on the wall surface, and roughening the coated surface is performed as preliminary work. The blast medium which is used in such an occasion is generally sand or steel as in Japanese Patent Application Laid-Open No. 2005-66724, but recently, a method of using a blast medium in the shape of a sponge piece with an abrasive bonded inside a porous elastic body, a so-called sponge blast method has attracted attention from the viewpoint of improvement in a working environment.
According to the sponge blast method, when the sponge blast medium ejected from a nozzle with high-speed air collides against a coated surface, the blast medium becomes flat, and the abrasive mixed therein directly collides against the coated surface at a high speed. Therefore, the coating film can be ground and removed as with a sand and steel blast method. Since generated powder dust is entrapped in the sponge, the advantage of improving a working environment is provided.
Incidentally, in the structure of the above described conventional blasting device, the force feeding device for blast medium is constituted of large devices such as the pressure tank and the blower of the main body, and therefore, much time is required for setup and much effort is also required. For the blasting operation for a region having a large area, the number of process steps required for the setup and the blasting operation efficiency can be kept in balance. However, for the blasting operation for a region having a small area, the blasting operation takes a short time as compared with the setup time, and therefore, the conventional blasting device has the disadvantage of the balance being extremely unfavorable.